coollogo_com-1399529.png
One way to screen capture is to download and use Jing)

Jing is screen capture software and a must in your toolkit for creating wikis and blogs. Download it from here
http://www.techsmith.com/download/jing/

How to use Jing

1. Once you have installed it move
your mouse over the sun icon
(at the right hand side of the mac,
or in the top middle of the screen
in.
Screen_shot_2010-09-30_at_8.28.50_AM.png
2. Click on the capture button
2010-09-30_0831.png
3. Click and drag around the
portion of the screen you want to capture.

Click on the Capture button Screen_shot_2010-09-30_at_8.47.11_AM.png
Use the tools to add arrows, text and add
boxes to highlight certain areas.
Screen_shot_2010-09-30_at_8.44.34_AM.png
4. Click on the Save button
Screen_shot_2010-09-30_at_8.50.58_AM.png



Macs

There are four ways you can take a screen capture.
One will save the screen capture to your desktop.
The other will paste straight to what ever document you have open.
The third will take a screen capture of the window you have open.
The fourth will take a screen capture your whole screen.

Save to your desktop
(you need to do this one if you want to keep the image to use again, like avatars or pictures that you want to upload to a wiki or blog)

Process:
Press Shift-Command-4 on the keyboardexternal image Picture+1.png.
Your mouse arrow will turn into a cross with a circle behind it.
Click and drag a rectangle shape around what you want to capture.
You will hear a camera click.
The picture will now be called Picture 1 and it will be on your desktop.
(If you are using this picture in a Wiki, make sure you rename it because if you upload another screen capture called Picture 1 then it will replace the one you have on your wiki and you won't be able to get it back.)

Paste straight to your document
Process:
Press Shift-Control-Command-4 on the keyboardexternal image Picture+1.png.
Your mouse arrow will turn into a cross with a circle behind it.
Click and drag a rectangle shape around what you want to capture.
You will hear a camera click.
Go to the document you want to insert the image into.
Press Command-V.
You cannot paste into a Wiki or a Blog! Use Save to the desktop for that one.

Screen Capture of Window (thanks to @cheesynz)
Process:
Press Shift-Control-Command-4 on the keyboard, then press the Spacebar.
Your mouse arrow will turn into a Camera icon,
Click on the window that you want to capture
You will hear a camera click.
Go to the document you want to insert the image into.
Press Command-V.

Screen Capture of whole screen (thanks to @tonitones)
Process:
Press Shift-Command-3 on the keyboard.
You will hear a camera click.
Go to the document you want to insert the image into.
Go to Insert Picture button, click on Desktop and select picture (or drag it off the desktop onto the document

OR
Press Shift-Control-Command-3 on the keyboard.
You will hear a camera click.
Go to the document you want to insert the image into.
Press Command-V.
=

Windows=

Take a Screen Capture (Win)

How to save a Screen Capture as a jpeg
Press Fn and PrtSc keys on Keyboard
Open Paint and press Ctrl V to paste

(Win 7)

Click on the Square Selector button external image square.png
  • click and drag around the part of the screen you want
  • click on the crop button
  • click on the Save icon (Floppy disk icon)
  • name it and save to Pictures folder
(Vista)

Click on the Square Selector button external image square.png
  • click and drag around the part of the screen you want
  • go to Image - Crop
  • select jpeg from Save as Type
  • click Save
(XP)
Click on the Square Selector button external image square.png
  • click and drag around the part of the screen you want
  • press Ctrl C to copy the selection
  • Open up PowerPoint
  • Press Ctrl V to paste
  • click on the picture then right click on the picture
  • select Save as Picture
  • name the file and save to your Pictures folder